<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>背景</title>
		<style>
			body{
				height: 10000px;
				width: 100%;
				background-color: azure;
				background-image: url(../images/jixue.jpg);
				background-repeat: no-repeat;
				background-attachment: fixed;
				background-position: right top;
				background-size: 40%;
			}
			#d1{
				
			}
		</style>
	</head>
	<body>
		<div id="d1">
			a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup>
		</div>
	</body>
</html>